This invention relates to an electric motor including apparatus effective to lock the rotor against rotation when the motor is not in use.
At present, motors designed for reversible operation under electric power can further be designed to resist reversing by external torque when electrical operation ceases, but only with a loss in overall operating efficiency. With an additional locking apparatus, however, such a motor can be designed for maximum efficiency in reversible operation and still resist rotation of the rotor by external forces when motor operation ceases. Such locking apparatus should lock and unlock the motor automatically with motor use.